(a) Field of the Invention
The present invention relates to a thermal reduction apparatus for metal production, a gate device of the thermal reduction apparatus, a condensing system of the thermal reduction apparatus, and a control method thereof.
(b) Description of the Related Art
A method of refining metal may be classified into pyrometallurgy, hydrometallurgy, electrometallurgy, and chlorine refining, and in the case of iron and most nonferrous metals, pure metal is obtained through the pyrometallurgy.
In a general pyrometallurgy process for nonferrous metal, metal, which is sintered in the form of a briquette, is heated at normal pressure or under a vacuum environment at a high temperature, and the pure metal is thermally reduced.
In order to refine magnesium metal using a thermal reduction method, briquettes mixed with reductants such as fired dolomite and ferrosilicon are loaded into a cylindrical retort made of metal, and the briquettes are heated at a high temperature.
When pressure in the retort is maintained in a vacuum state simultaneously with the heating, a magnesium oxide is reduced by the silicon, and magnesium vapor is generated.
The magnesium vapor is transferred by a vacuum pump to a condensing pipe installed at one side of the retort, and then begins to be condensed from an inner wall surface of the condensing pipe by thermophoresis (temperature), and magnesium is gradually accumulated in a central direction.
After the generation and condensation of the magnesium vapor are completed, the condensing pipe on which the magnesium is condensed is separated from the retort, thereby recovering the magnesium.
However, in the case of this batch type of manufacturing apparatus, there is a limitation in that productivity per day is limited because the reduction is carried out for a predetermined time, a thermal loss occurs in the retort because of discontinuous loading and unloading, and there is difficulty in automating processes consistently, and as a result, there is a need for a method of continuously and thermally reducing the magnesium.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.